What is the solution set for the quadratic equation x2 - 16 = 0? a) {4} b) {-4, 4} c) {256} d) {-256, 256}

B) {-4, 4} 

Proof:

Solve for x over the real numbers:
x^2 - 16 = 0

The left hand side factors into a product with two terms:
(x - 4) (x + 4) = 0

Split into two equations:
x - 4 = 0 or x + 4 = 0

Add 4 to both sides:
x = 4 or x + 4 = 0

Subtract 4 from both sides:

  x = 4 or x = -4